The present disclosure relates to an electrographic image forming apparatus and a toner case provided in the image forming apparatus.
In an electrographic image forming apparatus, a replenishment toner (a replenishment developer) is replenished on an electrostatic latent image formed on an image carrier (for example, a photoconductor drum) from a development device to form a toner image. The development device is connected to a toner case so as to replenish the replenishment toner from the toner case to the development device. The toner case configured to replenish the replenishment toner to the development device is attached to a first attached part provided in the image forming apparatus.
A waste toner (a waste developer) remaining on the image carrier after transferring the toner image on a sheet is removed from the surface of the image carrier by a cleaning device and then collected in the toner case. The toner case configured to collect the waste toner is attached to a second attached part provided in the image forming apparatus.
Some of the image forming apparatus having the above configuration use the toner case in combination for the purposes of the replenishment of the replenishment toner to the development device and the collecting of the waste toner. When such a configuration is applied, it is desirable to prevent the waste toner from being incorrectly replenished from the toner case, in which the waste toner has been collected, to the development device.
Consequentially, a configuration (hereinafter, referred to as “a first configuration”) configured to destroy a part of the toner case with the attachment of the toner case to the second attached part is provided. Alternatively, another configuration (hereinafter, referred to as “a second configuration”) in which a user pushes a handle down to detach the toner case from the second attached part is provided.
Still another configuration (hereinafter, referred to as “a third configuration”) is provided, in which an incorrect attachment prevention member movable in three positions including a position showing a new toner case, a position showing an empty toner case and a position showing a waste toner case is attached to the toner case and the above incorrect attachment prevention member is moved by an operation mechanism.
Furthermore, still another configuration (hereinafter, referred to as “a forth configuration”) is provided, in which a part of an intermediate gear provided in the toner case is destroyed with the attachment of the toner case to the second attached part so as to stop the rotation of a conveying screw in the toner case.
However, in the first configuration, since a part of the toner case is destroyed with the attachment of the toner case to the second attached part, it is difficult to reuse the toner case. In the second configuration, when a user may forget to push the handle down, the waste toner may be replenished to the development device and therefore it is difficult to prevent the replenishment of the waste toner to the development device.
Furthermore, the third configuration needs a special driving source (a motor or the like) configured to drive the operation mechanism to move the incorrect attachment prevention member, thereby causing an increase in manufacturing cost.
In the forth configuration, since apart of the toner case is destroyed with the attachment of the toner case to the second attached part, it is difficult to reuse the toner case, similar as the first configuration. And, in the forth configuration, a slight amount of the waste toner may be naturally fallen in the development device from the toner case.